1. Field of the Invention
This invention relates to an air cushion device for sports goods, and more particularly to an air cushion device including an extension tube, connected in a plane, "S"-shaped or zig-zag arrangement formed integrally with the cushion, and disposed either between two integrally formed cushions or between a cushion and a pressure pump to give free adjustment of the spacing between cushions or between a cushion and a pump without the necessity of making the connection by means of other components. The invention also concerns a pressure-limiting chamber formed integrally with the pressure pump, and having a preset or variable capacity so as to set the maximum value for pressurizing the cushion, whereby the pressure pump automatically will stop supplying air to the cushion once the inner pressure of the cushion reaches the value preset by the pressure limiting chamber. The present invention can be applied to a seat or saddle cushion, protection gear, shoes and other objects requiring the installation of a cushion.
2. Description of the Prior Art
There is a wide range of articles using the application of an air cushion as generally found in the present market. The cushion typically may comprise two sheets of material overlapped and sealed by heat, or the cushion may be cast with hollow dies. No matter how such a cushion may be manufactured, the prior art designs achieve a connection between cushions or between a cushion and a pump by using a separate tube. However, such a method of connection although it will achieve its purpose, increases the production costs with further time consumption and inconveniences in production while there is no way to guarantee that potential air leakage from the connection can be avoided. Therefore, the prior art in which an additional connection tube is used between two cushions or between a cushion and other components (namely, a pump, or pressure valve) fails to provide optimal effectiveness with regard to air leakage.
In addition, different spacing requirements may be needed between two cushions or between a cushion and another component (such as if one cushion is required to be installed in the sole of a shoe while a pressurizing component and other components are required to be disposed in the top quarter) depending on the size of the shoes, and shape of the shoes, or the type of shoe, for example, jumping boots, or ordinary shoes have different size and shapes. To manufacturers, it could mean the more difficult processes, more inventory and failure to practice a proper control of the sizes and quantities to be produced since there is a wide range of product sizes involved.
Furthermore, the requirement of having an additional connection tube disposed between the cushion and the pump in the design of cushion featuring an automated pressure pump will present problems of being vulnerable to air leakage. Also, a design of cushion using the automated operation on the pressure pump which is alternatively depressed under impact of the foot to pressurize the cushion and then released, generally will include a pressure release valve on the cushion capable of presetting the pressure by automatically releasing the pressure from the cushion when exceeding the preset value of the valve so that the cushion is preset at a constant maximum pressure value. The prior art using an air release valve to protect the cushion not only causes hardening over a certain area on the cushion resulting from the air release valve being made of metal, but also may result in injuries to the athlete when installed in sports shoes. Even though an air release valve mechanism can be positioned at a safe and proper position of the product, the connection tube will be exposed, leading to possible falling off of the connection tube or air leakage.